National Instruments R Series User Manual page 11

LED
USER2
USER3
Attaching External LEDs
Seven connectors on the device in the E1 part —1, 2, 3, 4, 5, 6, and 7— allow you to connect
an external LED circuit to the device, as shown in Figure 10.
For example, to connect an external USB READY LED, use 7 as the positive connection (+5
V) and 3 and the negative connection.
To connect the remaining LEDs, refer to Table 3.
National Instruments recommends that you limit the current to 10 mA per LED. You can limit
this current by using external resistors, as shown in Figure 9.
Table 3. LED Descriptions (Continued)
Description
Blue, user-defined
Blue, user-defined
Figure 9. External LEDs
1
2
3
Figure 10. Attaching External LEDs
OEM (On-Board)
1 6
NI USB-7846R OEM User Manual | © National Instruments | 11
4
5
6
7
+5 V
7
External
Resistor
External
LED
Location
4
5